Fluid flow and/or fluid pressure responsive gate weir

ABSTRACT

A fluid flow and/or fluid pressure responsive gate weir for the water outlet of swimming pools is provided, which responds to an increase in fluid flow through and/or fluid pressure in the weir, due to a flow surge or other condition that raises the water level of the pool at the weir, to close the outlet. When the excessive flow and/or pressure condition has subsided, or returned to normal, the gate weir responds to the diminished flow through and/or pressure in the weir to open the outlet again.

United States Patent Baker [54] FLUID FLOW AND/OR FLUID Q PRESSURE RESPONSIVE GATE WEIR [72] Inventor: William H. Baker, 403 Loudonville Road,

Albany, N.Y. 12211 [22] Filed: Jan. 18, 1971 211 App]. No.: 107,187

[52] U.S.Cl..... 4/l72.l7 [51] Int.Cl. ..E04h 3/16, E04h 3/18 [58] Field ofSearch...'.... ..4/172, 172.17, 172.18, 172.19, 4/l72.21,172. 15; 210/169 [56] References Cited UNITED STATES PATENTS 3,087,335 4/1963 Cavenah v ..2l0/l69 UX 3,155,989 11/1964 Anderson.... 3,173,865 3/1965 Bosico .......2l0/l69 as] June 13, 1972 4/1967 5/1967 1/1968 l/l97l Primary Eraminer-Henry K. Artis Anomey-Janes & Chapman ABSTRACT A fluid flow and/or fluid pressure responsive gate weir for the water outlet of swimming pools is provided, which responds to an increase in fluidflow through and/or fluid pressure in the weir, due to a flow surge or other condition that raises the water level of the pool at the weir, to close the outlet. When the excessive flow and/or pressure condition has subsided, or returned to normal, the gate weir responds to the diminished flow through and/or pressure in the weir to open the outlet again.

30 China, 9 Drawing Figures I imi" PATENTEDJun 13 I972 SHEET 2 OF 6 F/GZ PATENTEDJUH 13 I972 SHEET UF 6 lllmll 40 rum) FLOW AND/R FLUID PRESSURE RESPONSIVE 1 'cs'mwnm All swimming pools have to be provided with one or more water inlets and water outlets. When .the pool has a recirculating water system, it is conventional to build at least one of the water outlets in the form of an overflow or spillover. This may be associated with a skimmer, which utilizes the outlet flow to skim off surface debris and dirt from the pool.

In many cases, the overflow or skimmer outlet is not in continuous operation and is open only whenthe pool is not in use, such as overnight, afier the swimmers have left the pool for the day. For such purposes, a gate weir whose gate is manually opened and closed suffices to control the flow of water through that outlet or skimmer.

Nowadays, not all pool owners enjoy the chore of opening and closing a gate weir or skimmer and, accordingly, a number of devices have been provided to do so automatically; Typical devices of this type are described in US. Pats, No. 2,579,304 dated Dec. 18, 1951 to Crawford, No. 2,701,235 dated Feb. 1, 1955 to King, No. 3,316,934 dated May 2, 1967 to Sowers, and No. 3,428,178 dated Feb. 18, 1969 to Nash. These weirs are float-operated. The skimmeris operatively connected to a float which rides on the surface of the water in a skimmer pocket into which. the outlet leads. The float rises or falls, depending upon the level of the water in the skimmer pocket, and carriers the gate with it as it does so. The'water circulation pump is arranged to take up the water flow from the outlet, and when the water circulation pump is started up, the level of water in the pocket is lowered, and the weir gate tips down, so

water cascades overthe weir.-This flowcontinues while the pump continues to operate. When the pump ceases, thewater level'within the skimmer pocket rises to the same level as the water level in the pool, and so the float rises up with it, turning the weir to the closed position in which it serves as as barrier against return to the pool of debris within the skimmer pocket.

Over the years, swimming pools with perimeter gutter systems have come into widespread use, and these present special skimming problems. One type of perimeter gutter provides for flow of water over the top of the gutter wall into the gutter trough at all times. This provides a most efficient continuous skimming action under the usual water flow conditions, but as soon as swimmers enter the pool, or a heavy surge or wave action is encountered, the additional flow of water over the top of the gutter tends to flood thefgutter, after which all skimming action'is lost. In fact, some of the dirt already in the gutter may even be washed back. Such a gutter system is described in US. Pat. No. 2,932,397 dated Apr.,l 2, 1960 to Ogden. An older system of different design is describedin U.S. Pat. No. 1,797,397 dated Mar. 24, 1931, to Borraem et al.

It has been suggested in US. Pat. No. 3,363,767 dated Jan. 16, I968 to Ellis, that this condition can be alleviated if one or more skimming weirs are incorporated in the gutter at a lower level, below the top of the gutter. In this system, when the pool is not in use, the skimming weir is fully opened, and the skimming is'obtained via the gutter but at a lower level than the top of the gutter. When the pool is in use, the skimming weir is closed, and the water level is held down below the lip of the gutter, providing a reserve in-pool surge capacity, and helping to avoid a flooded gutter condition at the time of flow sur es.

I: accordance with the invention, a fluid flow and/or fluid pressure responsive gate weir for swimming pools is provided, comprising in combination, a weir support; a fluid flow passage in the support; a gatemember pivotably mounted in the support across the passage between flow-open and flowclosed positions; a gate control means'dis'posed to encounter a fluid flow through and/or fluid pressure in the passage above a predetermined minimum, and responsive to such flow and/or pressure to pivot the gate member from a flow-open towards a flow-closed position; and means arranged to retainthe gate member in the flow-open position under normal of conditions fluid flow and/or fluid pressure through the weir passage and to permit pivotal movement of the gate members towards a flow-closed position while such excessive fluid flow and/or fluid pressure continues.

Means can also be provided to. return the gate member to the flow-open position when such excessive flow and/or pressure subsides, and/or returns to normal.

A preferred embodiment of the invention comprises, in combination, a weir support; a fluid flow passage through the support; a gate member pivotably mounted in the support across the passage to move between flow-open and flowclosed positions, and having a control surface responsive to fluid flow and/or fluid pressure and which in the flow-open position is disposed to encounter a fluid flow and/or fluid pressure through the passage above a predetermined minimum, and responds to the motive force applied by such flow and/or pressure to pivot the gate member from the flow-open positions towards a flow-closed position; and a counterweight pivotable with the gate member and arranged to retain the gate member in the flow-open position under normal conditions of fluid flow and/or fluid pressure through the weir passage, and to permit pivotal movement of the gate member towards a flow-closed position while such excessive fluid flow and/or fluid pressure continues. The counterweight can also be arranged to return the gate member to the flow-open position when fluid flow and/or fluid pressure through the passage.

diminishes, to below a predetermined minimum.

This type of gate weircan be mounted in or across any kind of water outlet, to close the outlet under conditions of exces-' sive flow and/or pressure, above a predetermined minimum, however caused, and to reopen the outlet when flow and/or pressure returns to normal, or below the predetermined minimum. It can be in a skimmer opening, for example, and will be responsive to any excessive fluid flow and/or fluid pressure, such as arises from a flow surge, or an increase in fluid level of the-pool, due to swimmers entering the pool, to close the skimmer opening, and keep it closed while the condition continues. As soon as the water level or surge has subsided,

the gate member can be pivoted towards the open position,v

opening the skimmer, and permitting the normal skimming action to resumeflhis response can be repeated as often as necessary, in response to flow surges or waves, and in between the weir will still maintain a skimming action when possible under normal conditions. t

The fluid flow and/or fluid pressure responsive gate weir of a the invention is also responsive to a temporary or extended increase in the water level of the pool, to close an outlet or skimmer opening and permit the water'level in the pool to rise above that, for example, to the top of the gutter. The weir gate will remain closed until the water level subsides. The gate can also be made to respond to a gradualincrease in level of the pool, so as to only partially close the outlet or skimmer opening, permitting the excess water gradually to drain out,

without flooding the skimmer or gutter, and allowing the level to return to normal in due course. it can thus be made responsive to an increase in level due to the large number of swimmers in the pool at one time, preventing flooding of a gutter, but permitting the water level to return to normal at an acceptable rate. I

Any degree of response to any increase in fluid flow and/or fluid pressure above a predetermined minimum due to surge action, wave action, or water level increase can be arranged for by the design of the gate member and the gate control member. A number of structural embodiments are contemplated. In a preferred embodiment, the gate member is pivotably mounted across the flow passage through the weir support, so as to pivot between flow-open and flow-closed positions. In the flow-open position, the leading edge of the gate member is above the normal flow level. In the flow-closed position, all flow through the passage is cut off. Intermediate positions can be provided for.

The gate control member is responsive to fluid flow and/or fluid pressure in the flow passage to pivot the gate member towards a closed or partially closed position, and to hold it there. The gate control member can be from the gate member.

a part of or separate A separate gate control member can take the form of a float riding in the pool or in the flow passage, which triggers closing of the gate member whenever fluid level exceeds a predetermined minimum level. A paddle, which may be apertured, can be used, breasting the current of fluid flow in the passage but resisting movement at a flow velocity or pressure up to a predetermined maximum; when such flow or pressure is reached or exceeded, it moves, and triggers closing of the gate. The paddle can be pivotably or rotatably mounted, to swing or rotate with the flow, at a sufficiently high flow and/or pressure. The paddle can for example be biased by a spring, electromagnet or magnet in its normal position, but the bias means is arranged to yield and permit the paddle to move (and the gate member to move with it), whenever flow (or fluid pressure) exceeds a predetermined maximum. The fluid flow and pressure can provide the motive force for both paddle and gate member, and fluid pressure can hold the gate member closed.

if the paddle be apertured, the apertures act as orifices, which provide a sufficient flow capacity to pass normal flow but not excessive flow. Thus, at a predetermined maximum flow the paddle will move with the flow because of fluid pressure building up on the upstream side.

in these cases, the gate can be moved mechanically, such as by a spring, or by an electric motor actuated by movement of the flow-sensing member, such as by opening or closing an electric switch, or released and merely allowed to drop by gravity into a position where it is pushed by the flow to a closed position.

Flow or water levels in the passage above a predetermined minimum can also be detected electrically. Pool water is electrically conducting, and a pair of probes can be arranged at a height in the passage to be above normal flow but immersed in flow above the minimum. When immersed, an electric circuit is closed, and a solenoid and/or electric motor actuated to move the gate to a flow-closed position.

The gate control member can also be a part of the gate member. The preferred embodiment of this type is a pressure surface on the side of the gate facing the oncoming flow in the passage. Such a surface is large enough in area to respond to fluid flow in terms of velocity head and static head fluid pressure from an increased fluid flow through the passage, to close the gate, and to static head fluid pressure when the gate is closed, to keep it closed. In this case, no external motive force to .close the gate is needed; this is done by fluid pressure.

The member or means retaining the gate in an open position can also take a number of forms.

The gate can be magnetic, and magnetically held in an open and in a closed position by magnets in or beneath the walls of the flow passage, which in this case are of nonmagnetic material. The gate can also be or carry a magnet, and be retained by magnetic attraction to a magnetic passage wall in both the open and closed positions, in which positions it contacts or closely abuts these walls. If the gate be moved a short distance away from its open position by the gate control member, the forces of magnetic attraction are overcome, and the gate can move to the closed position.

' The gate can also be spring-biased in an open position, with the force of the spring selected to yield, and allow the gate to close, at a predetermined fluid pressure.

A preferred retaining member is a counterweight positioned to pivot the gate towards the open position.

The retaining member can be designed to retain the gate member (and its pressure surface, if there be one) in any position between horizontal (180) and a limiting position approaching the vertical (90), but sufficient to clear normal fluid flow, and to permit it to close to any position short of or up to 90 when in the, closed position, depending upon whether it is desired to close off flow through the water outlet either partially orwholly. The retaining force can be regulated to give any degree of movement of the gate in response to,

flow, so as to close partially, in response to a small flow increase, and wholly to a large flow increase, if desired. Suchresponse is easily obtained by balancing the" retaining force against the closing force, such as by adjustment of the area of the pressure surface facing the oncoming water flow.

In the case of a gate member including a fluid flowand/or fluid pressure responsive pressure surface, the leading edge of the gate member is arranged to clear the bottom of the flow passage over which it is disposed at a height sufficient to permit normal water flow through the passage to pass beneath it. The pressure surface of the gate member which is behind the leading edge thus is above the flow, and is inactive. ,Upon an increase in flow sufficient to encounter the leading edge, the flow then runs up upon or against the pressure surface. This water exerts a velocity and static head of fluid pressure upon the surface whose magnitude is a function of the amount and rate of flow of water encountering the surface, and the area of the surface. The retaining member, for example, the counterweight, provides sufficient balancing force to retain the gate member in the open position until theflow or the water pressure on the pressure surface exceeds the predetermined minimum, whereupon it becomes sufficient to move the gate member'pivotally downward towards the closed position.

The pressure surface of the gate member can be flat or curved, and if curved, it can be concave, convex, or in any desired curved configuration. The surface can be smooth and regular, or uneven, grooved, indented, or dimpled, or even slotted or apertured to obtain a finer degree of sensitivity and control of the flow response. A concave surface has a greater tendency to respond to a small flow increase, and increases sensitivity, while a convex surface has a lesser tendency to respond to small flow increases, and decreases sensitivity; a flat surface is intermediate.

The gate member is best pivotably mounted along one side or at one end, and the pivotalmounting is space sufficiently far from the leading edge to provide within the confines of the flow passage or outlet the area of pressure surface required for response under the flow conditions which are to be encountered. It will be appreciated that these parameters are easily determined for any given pool, and the area of pressure surface necessary under these conditions can be calculated using conventional formulas and equations. Since the pressure applied to the pressure surface is a function of water flow, the gate weir of the invention is truly flow-responsive, even though such response may be to a change of fluid level or fluid pressure, as well as fluid flow.

The gate member can be supported in any convenient manner suitable for the outlet or flow passage. A mounting across an open U- or V-channel support at the top of a perimeter gutter is satisfactory. The gate can also be supported across a passage through an enclosed weir housing. Both types are illustrated in the drawings.

The weir gate and support or housing as well as other components can be made of any desired material. Metals which are resistant to corrosion by water and weather are preferred, such as stainless steel, aluminum, anodized aluminum, galvanized iron and zinc, and porcelain or ceramic or glass coated metals. The weir components can also be made of plastic material, such as polytetrafluoroethylene, nylon, polyethylene, polypropylene, polycarbonates, polyoxymethylene, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, polyallyl, polyester, and polyurethane resins, as well as hard synthetic rubbers.

The leading edge of the gate member can be provided with a sealing gasket or ring, or the gate member can be arranged to seat against a sealing gasket or ring when in the closed position, to ensure a snug leak-tight fit when the gate is closed.

Preferred embodiments of the invention are illustrated in the drawings, in which:

FIG. 1 represents a view of the perimeter 'gutter of a swimming pool provided with a through skimmer passage including a flowand pressure-responsive gate weir in accordance with the invention;

FIG. 2 represents a view in cross-section of the weir of FIG. 1, taken along the lines 22 of FIG. 1;

FIG. 3 represents a view in cross-section of the weir shown in FIG. 2 with the gate in a closed position, after response to an increase in flow through the skimmer passage;

FIG. 4 represents a view of another type of perimeter gutter including a through skimmer passage fitted with a flowand pressure-responsive gate weir of the invention;

FIG. 5 represents a view in cross-section of the weir of FIG. 4, taken along the lines 55 of FIG. 4;

FIG. 6 is a front view partly in section of the weir shown in FIGS. 4 and 5;

FIG. 7 is an isometric view of another type of perimeter gutter including a through skimmer passage fitted with a fluid flow and fluid pressure responsive gate weir of the invention;

FIG. 8 is a view in cross-section of the weir shown in FIG. 7;

FIG. 9 is an isometric view of another embodiment, in which the weir gate is supported in a channel support.

The flow-responsive gate weir shown in FIGS. 1 to 3 is installed in a swimming pool 1 provided with a tile perimeter gutter 2. This gutter system includes a perimeter tile coping 3 with an open tile trough 4 beyond and below the coping. At spaced positions along the gutter 2 are provided a number of skimmer outlets 5, longer than they are high, and providing via through passage 6 a direct communication between the swimming pool 1 and the gutter trough 4. In normal pool use, there is a steady skimming water flow across the bottom of the skimmer opening into the gutter and the water flow maintains a relatively constant level at 7 in the pool 1.

Each skimmer opening is provided with a flow and pressure responsive weir 10. This weir comprises a rotatably supported gate member 11, pivotally mounted at its top rear edge 12 on the pivot pins 8, in sockets 9 on the side walls 13 of passage 6. The gate extends from side to side across the outlet opening 5, and its end barely clear the side walls 13 of the passage 6. The gate member has a flap 14 extending therefrom on the other side of the pivots 8, and to this flap is attached a counterweight 15. The counterweight is attached to the flap by bolts 16 which extend through the slots 17. The slots run radially along the flap with respect to the pivot pins 8, so that the counterweight can be adjusted in position in the slots, towards or away from the pivots 8, thus varying the counterbalancing force thereof on the gate member 1 1.

Extending outwardly from one side wall 13 of the passage 6 is a stop 18, which can be adjusted in a slot 19 along the wall so as to encounter the upper or pressure surface 20 of the gate member 11 at any position therealong, from the leading edge 22 to the pivoted edge 12. This stop is thus arranged to hold the gate member 11 at any desired limiting position up to a horizontal position. In such limiting position, the leading edge 22 of the gate member is held above normal flow level 7 through the passage 6, high enough to encounter only flows above a predetermined minimum level 23. I

The counterweight 15 is positioned in slots 16 along the flap 14, so as to retain the pressure surface of the gate member against the stop under all normal operating conditions, up to the predetermined minimum flow level 23. When this level is reached, however, and the water flow encounters the leading edge 22 and pressure surface 20 of the gate member, the counterweight balancing force is eventually overcome, to allow the gate member 11 to pivot towards the bottom of the passage 6, closing off the outlet 5.

In operation, the flow and pressure responsive weir functions as follows. At the normal pool level, water flows continuously below the gate through the passage 6 at level 7 into the gutter trough 4. Whenever the pool level rises and flow increases so that the water level or a surge or wave entering the passage 6 becomes high enough to reach level 23 and encounter the leading edge 22 of the gate member 11, the water is scooped up upon arid runs along the pressure surface 20. When the velocity and static head pressure of the fluid flow along this surface overcomes the balancing force of the counterweight 15, the gate is pivoted downwardly towards the closed position shown in FIG. 3, and it remains in that position under static head pressure while the higher fluid level contrnues.

The time required for the gate to close depends on the pivot joint. The traverse time from the open position shown in FIG. 3 can be a matter of a fraction of a second, if the water surge or wave is fast, and the pivot moves rapidly; movement of the pivot and gate can be slowed by a spring or dash pot to give a slow reaction, so as to respond only to a lasting increased flow or water level condition.

The gate 11 is held in the position shown in FIG. 3 by static head pressure until the water level, surge or wave subsides. Eventually, when the water level has returned to normal, or nearly so, static head pressure diminishes sufliciently so the force applied by the counterweight is sufficient to move the gate back to the position shown in FIG. 2. As soon as the leading edge 22 of the gate has moved above the fluid level of the flow along the bottom of the passage 6, skimming flow resumes.

The perimeter gutter shown in FIGS. 4, 5 and 6 has a poolside clean water feed conduit 31 and a trough 32 on the other side thereof. The top wall 33 of the gutter serves as'the edge coping at the top of the pool. This perimeter gutter is made up of a number of modular units 30, of which one is shown in FIG. 4, which are fitted together about the perimeter of the pool in the course of the construction of the pool, being bonded together at their abutting ends by welding, brazing or soldering. This gutter is formed of a sheet of stainless steel, which is shaped with the top 33 serving as the coping about the perimeter of the pool, the open trough portion 32 formed with upstanding sides 35, 36 and a bottom 37. The side 36 is in fact made up of two sections, bonded together by welding; a lower flange 38 extending upwardly from the bottom 37 of the gutter trough 32, and the side 36 of the closed-water feed conduit 31.

The conduit 31 has a bottom 40, an upstanding pool-side wall 4l, and a top 42. The pooLside wall 41 serves as a retaining wall for the pool water, as is best seen in FIG. 5. The wall 41 of spaced modular units 30 about the pool side contains a narrow, substantially horizontal slot 44, in which is snugly fitted, in a press fit, and bonded, if desired, by brazing, welding or soldering, or by an adhesive or synthetic resin bonding agent, a stainless steel flow-and pressure-responsive weir of the invention. Each weir comprises a weir support 45 with a trough passage 46 and a gate member 47. Water flowing through the skimmer passage 46 flows into the gutter 32 and water flowing over the top 42 of the closed-top conduit 31 also enters the gutter 32.

The weir has a design generally similar to that-shown in FIGS. 1 to 3 except that it is provided with its own housing. This makes assembly on-site easy, since all modular units 30 can be provided with slots 44, and the weir support and associated parts are fitted in thoseto carry the skimmers, while the others are closed off. This structure also facilitates servicing, replacement, or repair of weir units during the life of the pool.

The gate 47 is pivotally mounted at its rear edge 48 on an axle or hinge 50, which rotates in bearing sockets 51 in the side walls of the passage 46. The gate 47 has a flap 52 on the other side of the axle 50, which carries a counterweight 53. A magnet 54 on gate 47 holds the gate against magnetic stop 55, which is of iron or like magnetic material. The counterweight balances the gate against the stop, and the magnet holds it there, and prevents chattering on a windy day, or with small surges or waves, buthas insufficient force to retain it against the stop in event of an increase in flow above a predetermined minimum.

In operation, the leading edge 56 is well above normal flow level at 57. If flow increases beyond a predetermined minimum level 58, where it encounters the leading edge 56,

such as due to a wave or surge, or a large number of swimmers entering the pool at one time, the velocity and static head pressure of the flow scooped up by the gate eventually overcomes the force of the counterweight and magnet and the gate swings down to close ofi the passage 46, and is held there by static head in the passage. When the fluid level subsides, the counterweight returns the gate to a stop-abutting position, where it is held by the magnet.

Thus, during normal flow, the skimmer action is provided by the flow and pressure responsive weir passage 46, such water entering the passage 46 and gutter 32, and being fed back through the pool recirculation system by way of the filter and pump to the water feed intake for the pool. When swimmers enter the pool, the water level'may rise to above the predetermined minimum 58, in which event the gate 47 closes, and skimming action halts. An adequate in-surge flow capacity is provided by the additional height of the wall 41 between the weirs and the top 42 of the conduit 31. Wave action or surges beyond the predetermined maximum flow over the top 42 into the gutter 32, whence the water is again carried by way of the pool recirculation system back to the pool.

The perimeter gutter 60 shown in FIGS. 7 and 8 has a poolside clean water feed conduit 61, a pool-side skimming-flow gutter conduit 62, and an open gutter trough 63 on the other side of the gutter conduit 62. This perimeter gutter 60 is made up of a number of modular units, of which one is shown in FIG. 7, which are fitted together about the perimeter of the pool in the course of the construction of the pool, being bonded together at their abutting ends by welding, brazing, or soldering. This gutter is formed of a sheet of stainless steel which is shaped at one end to form the coping 65 about the perimeter of the pool, from which a continuation as upstanding wall 64 extends to define the bottom 68 of the enclosed gutter conduit 62, and terminates in a flange 69 which is bonded by welding, brazing or soldering to the enclosed water feed conduit 61 at the inner wall 70 thereof. The open gutter trough portion 63 is formed of another sheet of stainless steel shaped to define the gutter bottom 67, the edge thereof abutting the side wall 64 being bonded thereto by welding, brazing or soldering, the side wall 66 of the open trough gutter 63, and the top wall 77 of the perimeter gutter at the pool edge, terminating in side wall 76 at the perimeter of the pool.

The conduit 61 is formed of a third sheet of stainless steel, which is folded around to define the conduit, and the ends bonded together by welding, soldering or brazing at 71, thus defining a top wall 72, a pool side wall 73, a bottom 74, and a gutter side wall 70. The pool side wall 73 is provided with a number of inlet openings 75, for introducing clean feed water into the pool below the water level thereof. The end of wall 73 abuts and is bonded to side wall 76 at flange 79, at the end of the piece of stainless steel sheet defining the gutter trough 63.

1 It will be apparent that the skimming-flow gutter conduit 62 is defined by bottom wall 68, sidewall 70, top wall 72, side wall 76, top wall 77, side wall 66, bottom wall 67, and side wall 64. v

A portion of each of side walls 66, 76and top 77 at the top of the skimming-flow gutter conduit 62 is cut out, providing a recessed opening 78 in which is fitted a flowand pressure responsive weir 80 in accordance with the invention. This weir includes a weir housing 81, made of molded plastic, although it can also be of stainless steel, and provided with a top 82, bottom 83, and side walls 84, and a through passage 85 therewithin, opening at 86 onto the pool side to the pool, and at 87 on the opposite side onto the gutter trough 63. The bottom 83 of the weir housing 81 has a narrow open slot 88, extending all the way across the bottom 83 and longitudinally of the perimeter gutter, and serving as an inlet opening into the enclosed gutter conduit 62.

v The weir housing 81 is securely bonded by an adhesive in a leak-tight fit to the walls 66, 76, 77, of the skimming-flow gutter conduit 62, and the top 82 of the weir housing 81 is flush with the top 77 of the conduit 62. I

It will be apparent that the passage 85 serves as a skimmer passage for the pool, which is normally at the level shown in FIG. 8, so that a skimming flow of water can flow outwardly from he pool through the passage 85 to the slot 88, where it enters the skimming-flow, gutter conduit 62.

Pivotably mounted across the passage 85 is a weir gate 89, which has a design generally similar to that shown in FIGS. 1 to 3, except that it is supported within weir housing 81. Provision of the housing 81 makes assembly on-site easy, since all modular units 60 can be provided with the recesses 78 shown,

and the weir housing and associated parts are fitted in those units which are designed to carry the skimmers and the weirs, while the others are closed ofi. This structure also facilitates servicing, replacement or repair of weir units during the life of the pool.

The gate 89 is pivotably mounted at its rear edge 90 on pivot pins 91, which rotate in bearing sockets 92 in the side walls 84 of the weir housing 81. The gate 89 has a flap 93 on the other side of the pivot pins 91, and this flap carries a counterweight 95. The top 82 of the weir housing 81 is provided with a downwardly extending flange 97 at the inlet to the passage 85, and this serves as a stop, limiting the pivotal movement of the gate 89 to the position shown in FIGS. 7 and 8. The counterweight balances the gate against the stop, and holds it there, with its leading edge 94 in a position well above the normal fluid level of the flow in passage 85.

In operation, the leading edge '94 of the gate 89 is well above the normal flow level in passage 85. If flow increases beyond the predetermined maximum level, to level 96, the flow encounters the leading edge 94 of the gate 89. The velocity and static head pressure of the flow scooped up by the leading edge 94 of the gate eventually overcomes the force of the counterweight 95, and the gate 89 swings down, to the dotted line position shown in FIG. 8, to close off the passage 85, and is held there by static head fluid pressure in the passage. When the fluid level subsides below the level 96, static pressure eventually diminishes to the point where the force applied by the counterweight 95 returns the gate 89 to the stop-abutting position, where it is held by the counterweight until flow once again exceeds the predetermined maximum.

During normal flow, the skimming action is provided via the passage 85, such water entering the passage 85, passing through the slots 88 into the conduit 62, whence it is fed back through the pool recirculation system, after cleaning by filtration or other means to remove the debris carried by the skimming flow, into the conduit 62, after which the clean water is pumped to the water feed conduit 61, and returned to the pool via inlets 75.

When swimmers enter the pool, or if the waterlevel increases for some other reason, and the water level rises above the predetermined minimum, the gate 89 closes, and skimming flow via passage 85 halts, and remains halted for so long as the water level remains above the predetermined maximum. During this condition of thepool, an adequate in-surge flow capacity is provided'by the additional height of the pool side wall 76 between the skimmer passage 85 and the top 77 of the conduit 62. Wave action or surges beyond the predetermined maximum flow over the top 77 of the conduit 62 into the open gutter 63, whence the water is again carried by way of the pool recirculation system 'back through conduit 61 to the pool, after cleaning.

In the event that the surge flow or wave action flow over the top 77 of the conduit 62 is very large, and is sufi'rcient to fill the gutter 63 to the level of passage 85, the gutter does not rise above this level to a flooded level at the top 77 of the conduit 62, because a reserve gutter capacity is provided by the gutter 62. Access to skimming-flow gutter conduit 62 is provided by the open end 87 of the passage 85, with flow therethrough via slot 88. Such access is open even though gate 89 is closed. This additional flow capacity is more than adequate to accommodate any excessive surge or wave flow across the top 77 of the conduit 62, and thus the gutter system is not susceptible of being flooded under any conditions while the gate 89 is closed.

FIG. 9 shows another embodiment of weir, similar to that of FIGS. 7 and 8, but with the gate 89 mounted across a weir housing in the form of an open U-channel 100, in lieu of the closed housing 81 shown in FIGS. 7 and 8. This construction is in fact similar to that shown in FIGS. 7 and 8 in every respect, except that the top 82 of the weir housing 81 is not present. In this case, the stop 101 limiting pivotal movement of the gate 89 under the counterbalancing force of the counterweight projects from the side wall 84 of the channel, and skimming flow moves along the bottom 102 of the channel. Since the remainder of the construction is similar to that of FIGS. 7 and 8, further description is unnecessary, and operation thereof will be clear by reference to the preceding description.

The perimeter gutters and weirs shown in FIGS. 4 to 9 are madeof stainless steel, but it will, of course, be understood that other metals can be used, such as galvanized iron and steel, and aluminum, as well as anodized aluminum. Whatever the metallic material, its surface should be treated so as to render it corrosion-resistant, as by plating, galvanizing, anodizing, porcelain-enamel coating, or painting. It is also possible to form the perimeter gutter and/or the weir of plastic material, either in whole or in part. There are plastics now available which are sufficiently strong to withstand the wear and tear of a perimeter gutter system, including, for example, acrylonitrile-butadiene-styrene resin, polycarbonate resin, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyesters, polypropylene, polyamides, and synthetic rubbers such as polyisoprene, polybutadiene, butadienestyrene copolymers, and butadiene-isoprene copolymers.

The preferred construction is from a sheet or several sheets of metallic or plastic material, which are formed into the desired configuration, 'as is seen in the cross-sectional drawings. It is usually preferred that the coping portion at the top rear of the perimeter gutter extend at least partially, and preferably wholly, across an open gutter trough, so as to prevent people from stepping or falling into the gutter. Such can also be prevented by covering the gutter with a grating or grid of metal or plastic, the same or different material from the gutter.

The use of modular units, such as are shown in FIGS. 4 to 9, is preferred, because this permits mass production of the gutter and weir system at a point remote from the swimming pool, with easy and inexpensive transportation from that point to swimming pool construction sides anywhere in the world. The modular units can then be assembled on site to form any type or configuration of swimming pool, and any desired weir arrangementThe modular units can be made in straight sec tions for rectangular or other straight-sided pool shapes, while curved sections can be made for pear-shaped, elliptical, circular, or other curved-side pool configurations.

The modular units can be fitted together by welding, soldering or brazing, in the case of metal units; by bonding, using various types of adhesives, in the case of metal or plastic units; or by heat-sealing, ultrasonic welding, or heat-bonding, in the case of thermoplastic plastic units. Plastic units which are not fully heat-cured can be bonded and then cured in situ to form a permanent bond on site, in the course of construction of the pool.

The perimeter gutter and weir system of the invention can be used completely around the perimeter of a pool, or only partially around the pool perimeter, as desired. The most uniform skimming action and gutter action is, of course, obtained when the entire perimeter of the pool is provided with such a gutter and weir.

While construction of the gutter and weir in the form of modular units has been described, it will also be appreciated from FIGS. 1 to 3 that the gutter and weir system can be formed on site in the configurations shown using concrete or plastic material, and can form an integral part of the pool wall, by casting or pouring into suitable frames, so that the material can harden and set in the desired pool and skimmer outlet shape. The construction of the gutter system is sufficiently simple so that this type of technique can be employed with good results. Since this requires more hand-work, however, and is therefore a more costly method of construction, it would not usually be preferred, particularly in the case of large pools, where construction costs may be too high to permit the luxury of a hand-made gutter system on the pool site.

The gutter and weir system can also be made from bricks or tiles, which are built up in the desired configuration. These can be the usual types of materials, preferably with a ceramic facing, so that it is leak-proof, with the tiles being bonded together with water-resistant adhesive or cement.

The swimming pool can be equipped with water filtration and cleaning recirculation systems. The gutters usually feed water therein to such systems by gravity. Pumps can be provided, and the gutters can also be provided with jet water inlets to direct a driving flow of water along the gutter, to flush out the gutters, and to drive water along the gutter towards the water recirculation system. Such jet water inlets are described in US Pat. No. 2,932,397 to Ogden, dated Apr. 12, 1960.

Other variations and modifications of the invention will be apparent to those skilled in the art.

Having regard to the foregoing disclosure, the following is claimed as the inventive and patentable embodiments thereof:

1. A fluid flow and/or fluid pressure responsive gate weir for swimming pools comprising, in combination, a weir support; a fluid flow passage through the support; a gate member pivotably mounted in the support across the passage between flow-open and flow-closed positions; a gate control means disposed to encounter a fluid flow and/or fluid pressure through the passage above a predetermined minimum and responsive to such flow and/or pressure to pivot the gate member from a flow-open towards a flow-closed position; and means arranged to retain the gate member in the flow-open position under normal conditions of fluid flow and/or fluid pressure through the weir passage and to permit pivotal movement of the gate member towards a flow-closed position while such excessive fluid flow and/or fluid pressure continues.

2. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 1, including means to return the gate member to the flow-open position when such excessive flow and/or pressure subsides and/or returns to normal.

3. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the means to retain the gate member in the flow-open position comprises a counterweight.

4. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the means to retain the gate member in the flow-open position comprises a spring.

5. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the means to retain the gate member in the flow-open position comprises a magnet.

6. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the control means comprises a flow-sensing means.

7. A fluid flow and/or fluid pressure responsive gate weir according to claim 6, in which the control means comprises a fluid pressure-sensing surface.

8. A fluid flow and/or fluid pressure responsive gate weir according to claim 7, in which the pressure-sensing surface is a surface of the gate member.

9. A fluid flow and/or fluid pressure responsive gate weir according to claim 8, in which the gate member under normal flow conditions is arranged at an angle from to to the horizontal with a leading edge to encounter and scoop up flow above the predetermined minimum, the pressure-sensing surface being an upper surface of the gate member behind the leading edge.

10. A fluid flow and/or fluid pressure responsive gate weir for swimming pools, comprising, in combination, a weir support; a fluid flow passage through the support; a gate member pivotably mounted in the support across the passage to move between flow-open and flow-closed positions, and having a flow-responsive pressure surface which in the flow-open position is disposed to encounter a fluid flow and/or fluid pressure through the passage above a predetermined minimum and responds to the motive force applied by such flow and/or pressure to pivot the gate member from a flow-open position towards a flow-closed position; and a counterweight pivotable with the gate member and arranged to retain the gate member in the open position under normal conditions of fluid flow and/or fluid pressure through the passage, and to permit pivotal movement of the gate member towards a flow-closed position while such excessive fluid flow and/or pressure continues.

l 1. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the counterweight is arrangedto return the gate member to the flow-open position when the excessive fluid flow subsides.

12. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the gate member is a flat plate, and presents a flat pressure surface to the excessive fluid flow.

l3. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the gate member is pivotably mounted along one end. I

14. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, comprising a stop against which the counterweight retains the gate member in the flow-open position.

15. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 14, in which the stop is arranged to retain the gate member in a position between 135 and 180 to the horizontal. g

16. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the counterweight is movable towards and away from the pivotal mounting, to adjust the retaining force applied thereby to the gate member.

17. A swimming pool comprising, in combination, a water outlet establishing water outlet overflow at a-predetermined water level in the pool, and a fluid flow and/or fluid pressure responsive gate weir in accordance with claim 1, adapted to close the water outlet upon an increase in fluid flow through the outlet above a predetermined minimum.

18. A swimming pool in accordance with claim 17, including a perimeter gutter system with the water outlet disposed to provide water overflow to the gutter.

19. A perimeter skimming gutter for swimming pools com-' prising, in combination, a gutter trough for disposition about the perimeter of a swimming pool, and adapted to carry water at a level below a predetermined level of water in the swimming pool; a retaining wall on the pool-side of the trough, over the top of which wall water may flow from the pool into the gutter trough; and at least one fluid flow and/or fluid pressure responsive gate weir in accordance with claim 1 disposed through the retaining wall below the top thereof, at a height to maintain a predetermined water level in the pool, and to provide a skimming flow of water through the weir passage at such predetermined water flow through the pool, the top of the wall being spaced above the weir at a height to retain the pool water within the pool perimeter when the weir is closed at water flows, wave actions, and surges up to a predetermined minimum, while allowing excessive flows, wave actions, and surges beyond such minimum to flow over the top of the wall into the gutter trough.

20. A perimeter skimming gutter for swimming pools in accordance with claim 19, comprising a clean' water feed conduit connecting with at. least one water inlet opening through the retaining wall leading to the pool.

21. A perimeter skimming gutter in accordance with claim 20, in which the feed conduit is closed at the top, and the gutter trough is open. 7

22. A perimeter skimming gutter in accordance with claim 21, comprising an open grid extending over the gutter trough.

23. A perimeter skimming gutter in accordance with claim 19, in the form of a modular unit adapted to be assembled end-to-end with other such units to form the perimeter gutter of a swimming pool.

24. A swimming pool comprising side walls and a bottom adapted to retain water therewithin, and, extending about the upper perimeter of at least a portion of one side wall thereof, a perimeter skimming gutter in accordance with claim 19.

25. A swimming pool in accordance with claim 24, including a water cleaning and recirculating system for collecting water flowing into and along the gutter trough, cleaning it, and returning it to the pool.

26. A swimming pool in accordance with claim 24, in which the water cleaning and recirculating system includes a water filter for cleaning the water and a water pump for returning the clean water to the pool.

27. A perimeter skimrrung gutter for swimming pools in accordance with claim 19, comprising a second gutter receiving the skimming flow of water through the weir passage.

28. A perimeter skimming gutter for swimming pools in accordance with claim 27, comprising an overflow outlet leading from the gutter trough to the second gutter.

29. A perimeter skimming gutter for swimming pools in accordance with claim 28, in which the overflow outlet is the weir passage and skimming flow opening into the second gutter.

30. A swimming pool comprising side walls and a bottom adapted to retain water therewithin, and, extending about the upper perimeter of at least a portion of one side wall thereof, a perimeter skimming gutter in accordance with claim 27. 

1. A fluid flow and/or fluid pressure responsive gate weir for swimming pools comprising, in combination, a weir support; a fluid flow passage through the support; a gate member pivotably mounted in the support across the passage between flow-open and flow-closed positions; a gate control means disposed to encounter a fluid flow and/or fluid pressure through the passage above a predetermined minimum and responsive to such flow and/or pressure to pivot the gate member from a flow-open towards a flow-closed position; and means arranged to retain the gate member in the flow-open position under normal conditions of fluid flow and/or fluid pressure through the weir passage and to permit pivotal movement of the gate member towards a flow-closed position while such excessive fluid flow and/or fluid pressure continues.
 2. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 1, including means to return the gate member to the flow-open position when such excessive flow and/or pressure subsides and/or returns to normal.
 3. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the means to retain the gate member in the flow-open position comprises a counterweight.
 4. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the means to retain the gate member in the flow-open position comprises a spring.
 5. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the means to retain the gate member in the flow-open position comprises a magnet.
 6. A fluid flow and/or fluid pressure responsive gate weir according to claim 1, in which the control means comprises a flow-sensing means.
 7. A fluid flow and/or fluid pressure responsive gate weir according to claim 6, in which the control means comprises a fluid pressure-sensing surface.
 8. A fluid flow and/or fluid pressure responsive gate weir according to claim 7, in which the pressure-sensing surface is a surface of the gate member.
 9. A fluid flow and/or fluid pressure responsive gate weir according to claim 8, in which the gate member under normal flow conditions is arranged at an angle from 135* to 180* to the horizontal with a leading edge to encounter and scoop up flow above the predetermined minimum, the pressure-sensing surface being an upper surface of the gate member behind the leading edge.
 10. A fluid flow and/or fluid pressure responsive gate weir for swimming pools, comprising, in combination, a weir support; a fluid flow passage through the support; a gate member pivotably mounted in the support across the passage to move between flow-open and flow-closed positions, and having a flow-responsive pressure surface which in the flow-open position is disposed to encounter a fluid flow and/or fluid pressure through the passage above a predetermined minimum and responds to the motive force applied by such flow and/or pressure to pivot the gate member from a flow-open position towards a flow-closed position; and a counterweight pivotable with the gate member and arranged to retain the gate member in the open position under normal conditions of fluid flow and/or fluid pressure through the passage, and to permit pivotal movement of the gate member towards a flow-closed position while such excessive fluid flow and/or pressure continues.
 11. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the counterweight is arranged to return the gate member to the flow-open position when the excessive fluid flow subsides.
 12. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the gate member is a flat plate, and presents a flat pressure surface to the excessive fluid flow.
 13. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the gate member is pivotably mounted along one end.
 14. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, comprising a stop against which the counterweight retains the gate member in the flow-open position.
 15. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 14, in which the stop is arranged to retain the gate member in a position between 135* and 180* to the horizontal.
 16. A fluid flow and/or fluid pressure responsive gate weir in accordance with claim 10, in which the counterweight is movable towards and away from the pivotal mounting, to adjust the retaining force applied thereby to the gate member.
 17. A swimming pool comprising, in combination, a water outlet establishing water outlet overflow at a predetermined water level in the pool, and a fluid flow and/or fluid pressure responsive gate weir in accordance with claim 1, adapted to close the water outlet upon an increase in fluid flow through the outlet above a predetermined minimum.
 18. A swimming pool in accordance with claim 17, including a perimeter gutter system with the water outlet disposed to provide water overflow to the gutter.
 19. A perimeter skimming gutter for swimming pools comprising, in combination, a gutter trough for disposition about the perimeter of a swimming pool, and adapted to carry water at a level below a predetermined level of water in the swimming pool; a retaining wall on the pool-side of the trough, over the top of which wall water may flow from the pool into the gutter trough; and at least one fluid flow and/or fluid pressure responsive gate weir in accordance with claim 1 disposed through the retaining wall below the top thereof, at a height to maintain a predetermined water level in the pool, and to provide a skimming flow of water through the weir passage at such predetermined water flow through the pool, the top of the wall being spaced above the weir at a height to retain the pool water within the pool perimeter when the weir is closed at water flows, wave actions, and surges up to a predetermined minimum, while allowing excessive flows, wave actions, and surges beyond such minimum to flow over the top of the wall into the gutter trough.
 20. A perimeter skimming gutter for swimming pools in accordance with claim 19, comprising a clean water feed conduit connecting with at least one water inlet opening through the retaining wall leading to the pool.
 21. A perimeter skimming gutter in accordance with claim 20, in which the feed conduit is closed at the top, and the gutter trough is open.
 22. A perimeter skimming gutter in accordance with claim 21, comprising an open grid extending over the gutter trough.
 23. A perimeter skimming gutter in accordance with claim 19, in the form of a modular unit adapted to be assembled end-to-end with other such units to form the perimeter gutter of a swimming pool.
 24. A swimming pool comprising side walls and a bottom adapted to retain water therewithin, and, extending about the upper perimeter of at least a portion of one side wall thereof, a perimeter skimming gutter in accordance with claim
 19. 25. A swimming pool in accordance with claim 24, including a water cleaning and recirculating system for collecting water flowing into and along the gutter trough, cleaning it, and returning it to the pool.
 26. A swimming pool in accordance with claim 24, in which the water cleaNing and recirculating system includes a water filter for cleaning the water and a water pump for returning the clean water to the pool.
 27. A perimeter skimming gutter for swimming pools in accordance with claim 19, comprising a second gutter receiving the skimming flow of water through the weir passage.
 28. A perimeter skimming gutter for swimming pools in accordance with claim 27, comprising an overflow outlet leading from the gutter trough to the second gutter.
 29. A perimeter skimming gutter for swimming pools in accordance with claim 28, in which the overflow outlet is the weir passage and skimming flow opening into the second gutter.
 30. A swimming pool comprising side walls and a bottom adapted to retain water therewithin, and, extending about the upper perimeter of at least a portion of one side wall thereof, a perimeter skimming gutter in accordance with claim
 27. 